Turbine blade locking piece



April 6, 1943. J. R. HALL TURBINE BLADE-LOCKING PIECE Filed Jan. 28, 1942 Pic 1.

a rm \\I INVENTOR J IMES Ru HELL.

WITNESSES:

ATTORNEY Patented Apr. 6, 1943 TURBINE BLADE LOCKING PIECE James R. Hall, Chester, Pa., assignor to Westinghouse Electric & Manufacturing Company, East Pittsburgh, Pa, a corporation of Pennsyl- Vania Application January 28, 1942, Serial No. 428,491

4 Claims.

The invention relates to structure for filling the notches or gaps used for insertion of turbine blades and to function as a spacer for the adjacent blades and it has for an object to improve such structure to enable it to be assembled in place, joined, and taken apart by the employment of a simple procedure capable of being carried out in the limited available space.

A further object of the invention is to provide a locking piece for straddle root turbine blades wherein the piece or structure comprises complementary parts fitting in the filling notches for the blades and which have abutting portions overhanging the rotor rib and welded together, the arrangement being such that, incident to bringing the overhanging portions into abutting relation, the parts are locked to the rotor.

These and other objects are effected by the invention as will be apparent from the following description and claims taken in connection with the accompanying drawing, forming a part of this application, in which:

Fig. 1 is a fragmentary isometric View of a row of blades and a rotor;

Fig. 2 is a fragmentary side elevational view with one of the blades shown in section;

Fig. 3 is a fragmentary plan view looking down on the rotor;

Fig. 4 is a sectional view of the rotor taken along the line IV-IV of Fig. 5;

Fig. 5 is a fragmentary sectional view showing the complementary members of the locking structure in inclined position; and,

Fig. 6 is a view similar to Fig. 5 but showing the locking structure as finally assembled and connected.

In the drawing, there is shown a row of blades l having straddle roots I I and each of the roots has a T-shaped opening 12 to receive the rib 13 of T-section formed on the rotor M, the rib extending radially outward from the peripheral surface l of the latter.

The rib comprises a head l6 joined to the rotor by a web IT. Each root has lower portions or furcations l8 conforming to the flanges of the head 16 and having outwardly-facing bearing surfaces IQ for engagement with the inwardlyfacing bearing surfaces 2%! on the head flanges. Adjacent to the web, the rotor is formed with circumferential grooves 2| and the root furcations have toe portions 22 fitting in the grooves. The formation of the toe portions provides root bottom surfaces 23 for engagement with the rotor peripheral surface 15.

To provide for assembly and removal of the straddle roots over the rib, the head 16 has opposite notches or openings 24 formed therein and through which the portions !8 of the blade roots may be assembled in order to position the latter for engagement with the rib, whereupon each inserted blade may be moved around on the rib and circumferentially of the rotor incident to assembly of the row. After the blade row is assembled with blades disposed adjacent to the notched portion of the rib, it is necessary to attach a structure for spacing the adjacent blades and for filling the entrance openings or notches, and an improved means serving this purpose is the objective of the present invention.

As shown, the filling or locking piece or structure, at 25, is comprised by complementary halves 26 which fill the notches i l and have abutting or mating portions 21 overhanging the rib l3 and connected by a weld 28.

Each complementary half of the filling or looking structure has a toe portion 29 fitting in a groove 2| and a lug 30 for engagement in a recess 3| formed in the rib within the Zone of arcuate extent of the notches 24. With the complementary halves 26 assembled, the toe portions 29 fitting in the grooves 2|, the lugs 39 engaging in the recesses 3|, and the mating portions 21 abutting, the latter are Welded together; and to facilitate welding, each of the mating portions 21 is recessed at 32 (Fig. 5) to form a V-shaped groove or recess for the weld material 28.

From the structure described, it will be apparent that the weld 28 is accessibly located so that welding may be easily effected in the limited space available and the same is true with respect to chipping out the weld incident to dismantling the locking piece in order that blades may be replaced. In addition to ease of manipulation of the parts of the locking piece incident to its assembly and dismantling, these operations, as well as that of welding, may take place without in any way impairing the rotor.

As the lugs 30 fit in the recesses 3| and the outer faces of the toe portions 29 bear against or fit closely the outermost side walls of the grooves 2| when the locking piece is assembled and connected, it is necessary that clearance shall be provided to permit of assembly. Therefore, the toe portions have their inner corners beveled off, as shown at 33, and they are provided with outer notches 34. These features provide for insertion of the complementary halves 26 in an inclined manner (Fig, 5) and for rocking thereof to assembled position.

While the invention has been shown in but one form, it will be obvious to those skilled in the art that it is not so limited, but is susceptible of various changes and modifications without departing from the spirit thereof, and it is desired, therefore, that only such limitations shall be placed thereupon as are specifically set forth in the appended claims.

What is claimed is:

1. The combination with a rotor having a radially-extending rib of T-section and a row of blades having straddle roots defining openings conforming to the section of the rib and fitting the latter, the head portion of the rib having opposed filling notches; of a structure for spacing the blades of the row adjacent to the notches and comprising complementary members disposed in the notches and having abutting portions overhanging the rib, a weld connection between the overhanging portions, and means for holding the structure in place radially of the rib.

2. The combination as claimed in claim 1 wherein the holding means for the structure is comprised by lugs formed on the latter and engaging recesses provided in the rib.

3. The combination of the rotor having a radially-extending rib of T-section and circumferential grooves at the sides of the web portion of the rib and a row of blades having straddle roots defining openings conforming to the rib and fitting the latter, the head portion of the rib having opposed filling notches; of a structure for spacing the blades of the row adjacent to the notches and comprising complementary members disposed in the notches and having abutting 'portions overhanging the rib, a Weld connection between the overhanging portions, toe portions at the inner ends of the members and fitting in said circumferential grooves, and means for holding the structure in place radially of the rib, said toe portions being constructed and arranged to provide for insertion thereof into and removal thereof from the grooves with the members inclined with respect to the rib and to provide, when located in the grooves, for rocking of the members to bring the latter into assembled relation.

4. The combination of the rotor having a radially-extending rib of T-section and circumferential grooves at the sides of the web portion of the rib and a row of blades having straddle roots defining openings conforming to the rib and fitting the latter, the head portion of the rib having opposed filling notches; of a structure for spacing the blades of the row adjacent to the notches comprising complementary members disposed in and filling the notches and having abutting portions overhanging the rib, said rib having recesses formed therein at opposite sides and within the arcuate zone of the notches, lugs formed on the members and engaging in the recesses When the members are in assembled relation, toe portions formed at the inner ends of the members and disposed in the grooves so as to engage the outermost side walls of the latter when the overhanging portions are in abutting relation, said toe portions being formed with bevels at the inner and lower corners of the members and with notches formed in the outer sides of the latter near to the inner ends thereof to provide for insertion of the toe portions into and removal thereof from the grooves with the members inclined and for rocking of the members to bring them into position with the overhanging portions abutting, and a weld connection for joining the overhanging portions.

JAMES R. HALL. 

